Heart rate counter with digital storage and numerical readout

ABSTRACT

Apparatus for determining heart rate based upon the occurrence of two consecutive heart beats and for immediately displaying the determined heart rate in beats per minute. A transducer responsive to the occurrence of a heart beat generates an electrical pulse indicative of such occurrence. The heart beat pulses are applied, together with a train of clock pulses, to a counter which counts the number of clock pulses occurring between consecutive heart beats. A fully decoded, static, read-only memory has stored therein the different pulse rates which correspond to the different numbers of clock pulses which may occur between consecutive heart beats. By applying the output of the counter to the memory, the pulse rate which corresponds to the counted number of clock pulses may be selected. Such selected pulse rate is applied to a display device which visually displays the pulse rate in beats per minute.



1. Apparatus comprising: means for generating an electrical signal indicative of the measured time interval between consecutive heart beats; digital, read-only memory means having a plurality of address locations, each of said address locations containing a plurality of predetermined bits of digital information, said address locations being operative to store the different pulse rates which correspond to the different time intervals which may occur between consecutive heart beats, said electrical signal being applied to said memory means to select the address location having stored therein the bits of digital information indicative of the pulse rate corresponding to said measured time interval; and display means responsive to said bits of digital information at said selected address location for visually displaying said selected pulse rate.
 1. Apparatus comprising: means for generating an electrical signal indicative of the measured time interval between consecutive heart beats; digital, read-only memory means having a plurality of address locations, each of said address locations containing a plurality of predetermined bits of digital information, said address locations being operative to store the different pulse rates which correspond to the different time intervals which may occur between consecutive heart beats, said electrical signal being applied to said memory means to select the address location having stored therein the bits of digital information indicative of the pulse rate corresponding to said measured time interval; and display means responsive to said bits of digital information at said selected address location for visually displaying said selected pulse rate.
 2. Apparatus according to claim 1 wherein said memory means has stored therein pulse rates lying within a given range and signals indicating pulse rates outside of said given range, said signals being applied to said display means when said time interval indicates a pulse rate outside of said given range.
 3. Apparatus according to claim 2 wherein said display means comprises means for visually displaying a decimal number equal to said selected pulse rate when said pulse rate lies within said given range and a characteristic indication when said pulse rate lies outside of said given range.
 4. Apparatus according to claim 3 wherein said characteristic indication indicates whether said pulse rate is higher or lower than said given range.
 5. Apparatus according to claim 1 wherein said display means comprises means for visually displaying a decimal number equal to said selected pulse rate.
 6. Apparatus according to claim 1 further comprising: means for dividing consecutive time intervals between heart beats into two sets of mutually exclusive alternate time intervals, said generating means being operative during one set of said alternate time intervals, and said display means being operative during the other set of said alternate time intervals.
 7. Apparatus according to claim 1 wherein said generating means comprises: a source of clock pulses; and counting means for counting the number of clock pulses occurring between consecutive heart beats.
 8. Apparatus according to claim 7 wherein said address locations store the different pulse rates which correspond to the different numbers of clock pulses which may occur between consecutive heart beats, the count in said counting means being applied to said memory means to select the address location having stored therein the bits of digital information indicative of the pulse rate corresponding to the number of counted clock pulses.
 9. Apparatus according to claim 8 wherein said generating means further comprises: means responsive to the occurrence of a heart beat for generating a pulse indIcative thereof. 